Mumbai: Genome sequencing result of first batch of 200 to be out today

A woman gets tested for Covid at Dadar station on August 20. Fewer new cases have meant a smaller pool to choose samples from. Pic/Ashish Raje

The Brihanmumbai Municipal Corporation (BMC) has started the genome sequencing of 200 samples to detect virulent variants of the Coronavirus. The results and analysis of the tests are expected to be in on Monday. Though the new machine can test 384 samples in one go, right now, many samples are not available. Anticipating the third wave, the civic body has decided to go ahead with the smaller sample size.

A BMC marshal penalises a mask-less citizen at Marine Drive. File pic

The BMC's genome sequencing lab became operational at Kasturba hospital over two weeks ago on August 4. The tests started on Friday and the cycles were supposed to be complete by Sunday. The interpretation and analysis were to take another day.

Also read: Delta is reason for continuing COVID outbreaks: Genome sequencing panel

Waited for two weeks

The expensive genetic-level test requires samples meeting certain criteria and the civic body wasn't getting them due to the falling number of new cases in the city. As per the BMC's criteria, the samples are supposed to be collected from people who died after contracting Covid, patients who were seriously ill and were discharged after several days in the ICU, a cluster of cases in a particular place and cases with international travel history.

There weren't many samples and after waiting for two weeks, BMC decided to go ahead with the tests. Dr Jayanti Shastri, head of the department of microbiology and in charge of the lab, had said last week that they will start the process even with fewer samples.

The genome sequencing machine at the Kasturba Hospital lab

"The process started on Friday with around 200 samples that were selected for genome sequencing. We decided to go for a smaller sample size as there aren't many cases matching the criteria nowadays. A bigger sample size without any significant cases will give a false impression. We are expecting the results and further analysis by Monday," said Suresh Kakani, additional municipal commissioner.

Amid the pandemic, various strains have emerged with different characteristics such as ultrafast speed and serious symptoms. Genome sequencing uses genetic formulae to identify different strains or variants of the same virus and helps track patients, trace high-risk contacts and treat them. At present, 76 patients with the Delta plus variant have been reported in the state. Of these, 11 were reported in Mumbai. The tests are also done at the National Institute of Virology, Pune, but the results take two to three months due to heavy load.